1. Field of the Invention
This invention relates to a fuel feed pump, more particularly, to a fuel feed pump having a housing into which a pump and a motor for driving the pump are integrated, which is effectively employed, for example in a fuel feed pump for a vehicle.
2. Description of the Related Art
In general, in a fuel feed pump having a housing into which a pump and a motor for driving the pump are integrated, a brushless motor is employed. A control circuit unit for forming a rotation-magnetic field is necessary for a brushless motor; a unit of the control circuit unit is also generally integrated into the housing close to the brushless motor.
However, when the control circuit unit contacts fuel, electric corrosion, conduction and a short occur. Therefore, a fuel feed pump is proposed, in which a control circuit unit of the brushless motor is stored in a sealed casing, and a resin sealed portion is formed by a press-forming method (molding method) on a periphery of the sealed casing storing the control circuit unit, which is thereby constructed so as to prevent the contact with the fuel of the control circuit unit of the brushless motor (laying open of application No. 5-211738).
However, in the prior fuel feed pump hereinbefore, there are problems as follows.
(1) It is necessary to manufacture the sealed casing storing the control circuit unit so as to be able to bear the pressure of a press-forming of the resin sealed portion, so that the manufacturing cost is high. Furthermore, the pressure of a press-forming is restricted by the pressure performance of the sealed casing, so that the forming pressure can not be predetermined to a high pressure. PA1 (2) When press-forming the resin sealed portion, the temperature of the press-forming is restricted by the heat resistance of the elements in the control circuit unit, so that it is difficult to keep the accuracy of the forming. On the other hand, the whole control circuit unit is covered doubly by the sealed casing and the resin sealed portion, so that it is difficult to radiate the exothermicity of the control circuit. PA1 (3) As a forming material of the resin sealed portion, the use of thermosetting resin such as epoxy resin is necessary, so that oil proofing is a problem when using methanol fuel. PA1 the fuel feed pump comprising: